Lun Yu – The Analects of Confucius

Lunyu XI. 12. (279)

Confucius avoids answering questions about serving spirits, and about death.
Chî Lû asked about serving the spirits of the dead. The Master said, "While you are not able to serve men, how can you serve their spirits?" Chî Lû added, "I venture to ask about death?" He was answered, "While you do not know life, how can you know about death?"

Legge XI.11.

Chi-lu asked how the spirits of the dead and the gods should be served. The Master said, 'You are not able even to serve man. How can you serve the spirits?'
'May I ask about death?'
'You do not understand even life. How can you understand death?'